Platen printing press



Sept. 17, 1929. v. JERECZEK PLATEN PRINTING PRESS Filed May 20, 1924 y \\v M m M 0 x 5 7% 1M 0% m 9 Y Patented Sept. 17, 1929 UNITED STA ES uzasaa P T ENT town VIKTOR JERECZEK, OF LICI'ITENBERG, BERLIN, GERMANY, ASSIGNOR TO SGHNELLPRESSENFABEIK AKTIENGESELLSCHAFT HEIIDELBERG, OF HEIDELBERG, GERMANY, A CORPORATION OF GERMANY I l H I PLA'IEN PRINTING PRESS Application filed May 20, 1924, Serial No. nassafaiiaineernian na 28,1923. 1

My invention relates to platen printing presses and more particularly to a device for moving the platen of such presses.

\Vith platen printing presses, especially with. such of the type known as Bostonpresses, in which the platen swings on an axle lying about in its middle, the platen is moved by means of a connecting-rod actuated by the driving shaft of the machine. This known arrangement possessedof the drawback that, with high-speed machines, there does not remain sufficient time for the work-piece to take up the print, because the period of printing is too short therefor, which entails the necessity to obviate surpassing a certain limit of speed as otherwise the imprints ol tained are not of workmanlike quality.

The object of my invention is to obviate said drawbacks and I attain the effect intended by providing a toggle-joint lever connected at its joint with the above-mentioned connecting-rod, whereas the free end of one of its members is connected with the machine frame, and the free end of the other member is connected with the platen. Owing to this arrangement and combination of the parts mentioned, not only the compressive forces are transmitted to the frame of the printing press, which is counter to what takes place in printing presses of the known types, but, principally, the period of time during which the work-piece is pressed against the matter required for the printing is considerably longer, as the members of the toggle-joint lever remain aligned during a comparatively long part of the path of the driving crank.

The workpiece, i. e. the printing sheet, has, I

therefore, suflieient time to take up the ink, and the printing-presses provided with a toggle-joint lever arranged in the manner stated can run with a considerably higher speed so that their output is correspondingly greater. Besides, the platen with the workpiece is pressed against the matter 10 always appropriately strong as it is possible, owing to the suitable arrangement of the toggle joint lever, to re-adjust it when any one of the driving-parts concerned has been worn ofif, which permits also to regulate the strength of that pressure.

, My ,inventionisillustrated, e tample, in the accompanying drawing in which Figurel is partly aside-view of the platen and the {toggle-joint lever and partly a vertical section through a few adj acentstationary parts of the printing-press, and Figure 2 is partly a plan of the toggle-joint lever and partly, a horizontal section in line II ofFigl. l

1 is the main driving shaft-of the printingpress, and 2 a crank afiixed thereto and connected by the connecting rod 3 with the toggle-joint lever 4/ 5, the member l otfwhich is connected with a sleeve-shaped bearing .7 by a pivot 14:, whereas the nemberfi of the toggle-joint lever is connected with the downwardly extending lever arm 8 of the platen 8 by a pivot 15. The platen iscarriedhy an axle 0 supportedin thefframe 6 ofthe printing-press. The bearing 7 is secured to this frame, so that the abutment-pressure is taken up directly by the frame 6 whereby the rotary members are relieved andless subjected to- Wear and tear.

Owing to the insertion of the v lever between the'driving shaft l and the platen 8the length ofthe printing period is materially longer than with direct engage: ment of the connecting-rod at the platen, because the toggle-joint, lever is completely straight whenthe crank 2 and the connecting- .rodl3 arenearly 1n alignment andthe wrist of the crank is passing the dead center sothat the toggle-joint lever remains in its straight position during the passing-of the dead cen- .ter, as Wlll beunderstood.

When, owing to wear and tear of the joints or the likethe pressure which the platen ex erts on the printing face'lO is no more-sulficient, it is easily possible to make up therefor by're-adjusting the bearing 7 which is attached to the frame 6 by a strong pivot 13 I which is,turnably'supported in the frame and can also be re-adjusted longitudinally therein, firstly, by means of a bolt 11 which j thickness is inserted between the bearing 7 and the adjacent face of the frame-boss 6*"- in which the pivot 13 is supported. Owing to this pivot being rotatable in the boss 6, the bearing 7 can adjust itself, automatically, into that position in which the pivot 14 lies parallel to the other pivots of the toggle-joint lever. The bolt 11 is drawn fast when proper spacing-washer 12 has been inserted and the automatic re-adjustment of the pivot 13 has taken place, as described.

I claim: 1

1. In a mechanically driven platen printing press, in combination, a press frame, a main driving shaft journaled in said frame and arranged for rotating in one direction with uniform velocity, a crank affixed to said shaft, a platen having a lever arm, an axle horizontally arranged in said frame and on which said platen is arranged for rocking movement, a toggle joint lever having one arm connected to the lever arm of said platen, the other arm being turnable in a bearing connected to said frame, said bearing being turnable on a horizontal axis, a connectin rod having its one end connected to sai crank and its other end connected to the central oint of said toggle, said crank and toggle lever connection being arranged to bring said platen to its printing position, when said toggle lever is fully straightened and said crank is at dead center.

2. In a mechanically driven platen printing press, in combination, the frame of the press, the main driving shaft journaled in said frame and rotating in one direction with uniform velocity and having a lever arm, a crank aliixed to said shaft, the platen arranged for rocking movement on an axle horizontally arranged in said frame, a toggle joint lever having one arm connected to the lever arm of said platen, the other arm being t-urnable in a bearing connected to said frame, said bearing having a horizontal pivot journaled in the frame of the press, a screw for horizontally shifting said pivot and bearing, and a spacing member arranged on said pivot between the frame and said bearing, a connecting rod having one end connected to said crank and its other end connected to the central joint of said toggle, said crank and toggle lever connection being arranged to bring said platen to its printing position, when said toggle lever is fully straightened and said crank is at dead center. 7

In testimony whereof I'have aflixed my signature.

VIKTOR J ERECZEK. 

